DE3520394A1 - WOOD PRESERVATIVES - Google Patents

Abstract

1. A concentrate for impregnating solid wood in order to preserve the latter, based on a copper salt and monoethanolamine and, if required, a salt with a fungicidal anion, wherein the concentrate contains from 5 to 50% by weight of monoethanolamine and, if required, further alkali such that a pH of not less than 8 is established.

Description

Dr. Wolman GmbH » ■. :. '.Ό. ZL. 0975/000 ^ 7

Wood preservatives

The invention relates to the provision of means for the pressure impregnation of (solid) wood on the basis of aqueous preparations of copper salt, alkanolamine and optionally other Be Ingredients, especially fungicidal salts, the effect of which is based on the anion, such as boric acid salts.

For the protection of wood that is exposed to the elements or moisture or is installed in contact with the ground, so far, chromate-containing, fixing wood preservatives have been used. These wood preservatives are called aqueous, e.g. 2 to 6 /! solutions according to the later degree of danger of the wood to be impregnated are applied with the help of large-scale impregnation systems (boiler pressure impregnation).

For use in contact with the ground are due to the required effectiveness against mold rot, only agents that are used in addition to chromate Contain copper. A distinction is made between CK type (based on copper, chrome), CKB type (based on copper, chrome, boron), and CKF type (based on copper, chrome, Fluorine), CKA type (based on copper, chromium, arsenic).

These wood preservatives fix on the chromatarite part: After impregnation, the chromates react with the constituents of the wood by reducing them to III-valent chromium compounds, this increases the pH value in the wood, so that copper and chromium compounds in the wood become water-insoluble soluble compounds fail, they fix.

However, chromates, i.e. VI-valent chromium compounds, pose a significant risk to the environment if caused by leaks or weather

Due to the influence of weathering during the fixing process, washout occurs, so that surface water, ground water and drinking water are contaminated, the Maximum concentration value currently still regarded as tolerable is e.g. 0.05 ppm. Even if the chromium in the wood is converted into insoluble III-or VI-valent chromium compounds, which are then extracted from the Ash can be washed out; this gives rise to disposal problems.

So far, chromium-free, copper-containing, water-soluble wood preservatives have been proposed for large-scale impregnation, in which e.g. Copper arsenates and borates were converted into water-soluble alkaline form by complex formation with ammonia; by evaporation of the Ammonia and buffering through wood constituents (natural pH value of the wood is around 5), these agents are fixed in the wood. Independent of

Dr. Wolman GmbH ** - '· "' © .Ζ. 0975 / AQpSL

These impregnation solutions or the concentrates can lose their stability due to the evaporation of the ammonia, so that the odor nuisance Solutions for further impregnation are no longer suitable. If the ammonia content is insufficient, the Protective agent hindered into the wood.

Also amines, e.g. ethylenediamine, with good complexing properties were recommended for wood preservatives containing copper and fluorine to protect wood-based materials (e.g. chipboard); these agents are used in highly concentrated form mixed into the glue and sprayed onto the chips. They are not suitable for protecting solid wood, as the ethylenediamine complexes are also resistant to the wood's own pH values (5-6) are and not fix; they are washed out in the wood by water.

The copper can only be fixed if it is organic and water-insoluble Copper salts can arise. This is how wood preservatives were described that Copper salts of N-nitroso-cyclohexyl-hydroxylamiris (new name Copper salt of N-Cyclohexyldioxydiazeniumoxids, Cu-HDO) contain. That Cu-HDO is obtained via polyamines, e.g. ethylenediamine or diethyleritriamine in Wood protection concentrates transferred, which are dissolved in mass for impregnation will. They fix in the wood by buffering with the help of wood constituents from around pH 7.5. This fixation takes place so quickly that at the pressure impregnation prevents the penetration of the Cu-HDO. E.g. even in the easily soaked pine, the Cu-HDO only reaches an outer layer of about 10 to 15 mm; the distribution of protective agents from the outside to the inside decreases rapidly.

If other amines, e.g. alkanolamines, especially monoethanolamine, are used for If complexing is used, the Cu-HDO is only completely dissolved in highly concentrated solutions, when diluted with water to the application concentration tration it fails again.

It has now been found that the disadvantages described above are remedied can be, if you use water-thinnable agents made of (inorganic) copper compounds (water-soluble or insoluble, such as e.g. copper sulfate, copper fluoroborate, copper hydroxide, copper borate, Copper fluoride, copper carbonate, copper oxychloride with complex formation can be obtained with alkanolamines in aqueous solution, whereby a pH value of 8 or more must be established in the case of ready-to-use dilution.

The water-dilutable agents contain - in concentrated form - that Copper, calculated as an element, i.a. in an amount of 1 to 15 percent by weight.

ORIGINAL INSPECTED

Dr. Wolman GmbH · · f3 ^ - .. ^: * '0.2 975 / pT

Suitable concentrates contain, for example (in each case percent by weight)

5 to 50 tons of copper salt, 5 to 50 tons of alkanolamine

up to 50 l salt of a fungicidal anion up to 5 l free alkali up to 75 l of a quaternary ammonium salt,

where the total is 100 (weight Z) in each case,

and possibly minor amounts of other components, such as Amines, ammonia, corrosion inhibitors and, if necessary, mass, its share, however, i.a. can be kept low and is essentially used for handling. However, the invention extends equally on the impregnation plates, which can be produced by dilution with water, correspondingly lower individual concentration.

The complexation can take place in the presence of fungicidal anions such as e.g. Borates or fluorides. By dissolving the copper compounds in Alkanolamine, in particular monoethanolamine, optionally with the addition of water, results in highly concentrated water-soluble pastes or liquids Concentrates which, when dissolved in water, can be used to impregnate wood. The pH of the aqueous impregnation solutions is or above 8, especially at pH 9 to 10 (depending on the concentration). At the Impregnation in the boiler pressure process allows the copper component to penetrate well the wood one. The wood preservatives according to the invention are buffered during the impregnation by the wood acids contained in the wood, the From approx. PH = 7 copper precipitates in the wood; the complex forming power of Alkanolamines are no longer sufficient from pH 7 to 7.5, the copper in To hold the solution so that the copper is fixed in place. The copper fixation is of the same order of magnitude as in the previous chromate and copper-containing wood preservatives, ie it can be fixed on average about 90 to 95 I the copper component in the wood. The fixation is partly dependent on the additional alkanolamine content that is used for setting the pH value is required for strong acids or fungicidal anions; however, a certain amount of pH-shifting effect can also result Addition of e.g. alkali can be achieved, e.g. as much as is necessary to shift by up to 1 pH. Generally this concerns Measure the proportion of fungicidal anions or acid residues; he can un depending on the complex formation also by alkali, ammonia or others water-soluble amines can be adjusted to the necessary pH.

Dr. Wolman GmbH / ■ * 4 ^ - ',. '-0.2. O975 / OCOJ7

For economic reasons, it is particularly suitable as a complexing agent Monoethanolamiri; the production of the wood preservatives according to the invention is also possible with other alkanolamines e.g. isopropanolamine, 1-, 1.2-diaminoethanol, diethanolamine, dimethylethanolamine, etc. Here the amount of alkanolamines added is such that it is sufficient once to form a complex of the copper (1 g atom of copper generally requires 4 mol equivalents of amine) and, on the other hand, optionally alkanolamine salts of the additionally used fungicidal anions (fluoride, borate, Fluoroborate) or acid esters so that the aqueous impregnation solution has a pH of 8 or more, preferably around pH 9 to 10 adjusts.

The wood preservatives according to the invention can optionally contain customary additional components such as corrosion inhibitors, e.g. isonoric acid or contain their salts and in particular certain quaternary ammonium salts, which have a biocidal effect, as the following examples partly explain.

Suitable quaternary ammonium salts are, for example, those which ^{correspond to the general formula (R 1} R ² R ³ R ^ N) ⁺ Z ", where

R ¹ denotes an alkyl radical with 8 to 20 carbon atoms, an alkenyl radical with 12 to 20 carbon atoms or a benzyl radical which is optionally substituted by Ci-C2o-alkyl or halogen. R ^{2 is} Ci-C ₆ -AIkYl, R ^{3 is} Ci-C ₆ -AIkVl, R ^ Ci-C20-alkyl

or two of the radicals R ¹ to R ^ together with the nitrogen atom form a heterocyclic radical which contains 4 to 5 C atoms, 1 to 2 N atoms and one or two double bonds, the carbon atoms optionally being replaced by Ci-C ^ - Alkyl or halogen are substituted, and Z is an acid residue.

The following procedure was used to test the invention in practice:

The concentrates were diluted with water in the specified amount (4 or 3 l) and pine logs were soaked with it. It was used in accordance with DIN 52 172, sheet 2.

Dr. Wolman GmbH * ,. '-; JB ^ - ',.' ,. Q, 2. 0975-00037

example 1 From a mixture of

33.3 wt. Z CuSOVSH ₂ O

33.3 Gew.Z monoethanolamine

33.4% by weight of water

40 g to 1 liter are each dissolved in water (hereinafter referred to as "4 Zige Solution "called).

Copper leaching according to DIN 52 172, sheet 2: 7.5 Z. Example 2

20.0 wt. Z 3Cu (OH) ₂ -CuCl ₂

40.5% by weight of monoethanolamine 40.0% by weight of water

(4 Z aqueous solution) copper leaching according to DIN 52 172, sheet 2: 10.5 Z. Example 3

15.0% by weight Cu (OH) ₂ CuCO ₃ 16.0% by weight monoethanolamine 16.0% by weight aminoethanolamine 25.0 ZH ₃ BO ₃ 38.0 ZH ₂ O

(4 Z aqueous solution) washing out according to DIN 52 172, sheet 2:

Cu 10.5 Z B 85.5 Z.

Example 4

13.5 Z Cu (OH) ₂ ) 25.0 Z boric acid 17.5 1 monoethanolamine 17.5 Z aminopropanol 26.5 Z water

Or. Wolman GmbH -: * -. C, Z. 0975/00037

(4 I aqueous solution) leaching according to DIN 52 172, sheet 2:

Cu 7.7 I B 86.5 7.

Example 5

25, Ü I Cu (OH) ₂ CuCl ₂

16.0 I H ₃ BO ₃

5.0 t isononanoic acid

42.0 I monoethanolamine

12.0 I H ₂ O

(4 I aqueous solution) after leaching DN 52 172, sheet 2:

Cu 8.0 I B 84.5 I.

Example 6

50 I Cu (BFU ₂ 50 I in H ₂ O ^

30 I monoethanolamine 20 ZH ₂ O

(3 I aqueous solution, as defined above) leaching according to DIN 52 172, sheet 2:

Cu 10.5 7. F 70.0 I B 75.0

Example 7

16.5 Cu (OH) ₂ CuCO ₃ 10 t NH ^ HF ₂
36.0 monoethanolamine 3.5 ZH ₂ O

(3 Z aqueous solution) washing out according to DIN 52 172, sheet 2:

Cu. 0.5 IF 78.5 7.

Dr. Wolman GmbH ' - - _: X' - '· :. ■ '- 0.2. 0975/000 ^ 7

Example 8

15.0 CU (OH) ₂ CuCO ₃ 30 Z aminoethanolamine 25.0 Boric acid 27.0 Z H2O

U Z aqueous solution) leaching according to DIN 52 172, sheet 2:

Cu 12.5 Z B 88.0 Z.

Example 9

f5 70 Z copper borate paste (50 Z dispersed in water) 30 Z monoethanolamine

U Z aqueous solution) leaching according to DIN 52 172, sheet 2:

Cu 7.5 /. B ^- 85.0 Z.

Example 10

75 Z copper borate paste (50 Z dispersed in water) 25 Z monoethanolamine

(4 Z aqueous solution) washing out according to DIN 52 172, sheet 2: Cu 6.2z

B 66.1 Z.

Example 11

The salts according to the invention can also be used with other water-soluble salts Fungicides are mixed, e.g. quaternary ammonium compounds.

50 Z alkyldimethylbenzylammonium chloride (5Ö Z in water, alkyl = C12-C16) 15 I 3Cu (OH) ₂ CuCl ₂ 23 Z monoethanolamine 12 ZH ₂ O

Or. Wolman GmbH

X- ο. ζ. 0975 / C0037

(3 L aqueous solution) leaching according to DIN 52 172, sheet 2

Cu

8.5 I.

5 Comparative experiment

Chromium-containing salts:

U) Type CKB Cu I CuO 8th .6 Z .0 , 5 } in 7. 10 Content of Cr 13th , 4 7th .0 .5 Content of B. I ethylenediamine 4th , 4 .5 .5 Content of I KHF ₂ Washout 1b) Type CKF Cu I water 7th .7 ι 15th Content of Cr 25th , 5 ι Content of F. 14th , 5 ι Content of 1a) Type CKB 20th Cu Cr B. 1b) Type CKF 25th Cu Cr F. Comparison attempt 2 12.0 30th 22.0 12.0 54.0 13th 18th 72 Washout in Z 8th 2 93

3 '/ dissolved in water

Washout according to DIN 52 172.Sheet 2:

40 Cu

75.5 I 92.5 I.

Claims (5)

Dr. Uolman GmbH "C-Z. 0975/000 ^ 7 claims 1. Means for impregnating solid wood, in particular by means of the boiler pressure process, based on a water-dilutable preparation of a copper salt, an alkanolamine and optionally a salt with a fungicidal anion, characterized in that the alkanolamine and optionally further alkali are present in such an amount that upon dilution of the composition in a usual treatment concentration of about 1 to 5 wt. I non-aqueous components in the aqueous solution is adjusted to a pH of at least 8. 2. Composition according to claim 1, containing monoethanolamine. 3. Composition according to claim 1, additionally containing a boric acid salt or Boric acid. 4. Composition according to one of claims 1 to 3, additionally containing a quaternary ammonium salt. 5. A process for the pressure impregnation of wood, characterized in that an aqueous solution of a copper salt and an alkanolamine is used which has a pH of 8 or more. S. A process for the preparation of an impregnation liquor for the process according to claim 5, characterized in that an agent according to one of claims 1 to 3 is diluted with water, or a concentrate of a copper salt and optionally an alkanolamine is diluted and the pH of the liquor is through Adding an alkanolamine and, if necessary, alkali brings it to pH 8 or above. 0975/192/85 Mu / ro 05.06.1983
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